﻿using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace test001
{
    class Program
    {
        static void Main(string[] args)
        {
            //System.Nullable<int> nullableint;
            int? nullableint;
            nullableint = null;

            //if(nullableint==null)
            if (nullableint.HasValue)
            //Console.Write("在这里输入整型数据");


            Console.Write("空\n");
            //nullableint =Convert.ToInt32(Console.ReadLine());
            //Console.Write("你输入的是，{0}", nullableint); 
        }
    }
}
